﻿/* Copyright © 2008 by Marcus Bengtsson - makkbe@gmail.com   
 * 
 * This file is part of TaskDispatcher.
 *
 * TaskDispatcher is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * TaskDispatcher is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with TaskDispatcher.  If not, see <http://www.gnu.org/licenses/>.
 **/

using System;
using System.Collections.Generic;
using System.Text;
using System.Reflection;
using System.Configuration;
using Dispatcher.Logging;
using System.IO;
using System.Diagnostics;

namespace Dispatcher.Dispatching
{
    public class Deployer
    {
        private static Deployer instance = null;
        private String assemblyPath;

        /// <summary>
        /// Returns an instance of Deployer
        /// </summary>
        public static Deployer Instance
        {
            get
            {
                if (instance == null)
                {
                    instance = new Deployer();
                }

                return instance;
            }
        }

        /// <summary>
        /// Private constructor for Deployer
        /// </summary>
        private Deployer()
        {
            try
            {
                this.assemblyPath = ConfigurationManager.AppSettings["AssemblyPath"];
            }

            catch (Exception e)
            {
                Logger.Instance.Log(e);
            }
        }

        /// <summary>
        /// Search the specified AssemblyPath for assemblies containing ITasks
        /// </summary>
        /// <returns>A list containing ITasks</returns>
        public List<ITask> GetTaskList()
        {
            List<ITask> tasks = new List<ITask>();

            if (this.assemblyPath != null)
            {
                try
                {
                    DirectoryInfo dirInfo = new DirectoryInfo(this.assemblyPath);
                    FileInfo[] assemblies = dirInfo.GetFiles("*.dll");

                    foreach (FileInfo fileInfo in assemblies)
                    {
                        Assembly assembly = Assembly.LoadFrom(fileInfo.FullName);
                        Type[] types = assembly.GetTypes();
                      
                        foreach (Type type in types)
                        {
                            try
                            {
                                Object o = Activator.CreateInstance(type);

                                if (o is ITask)
                                {
                                    Logger.Instance.Log("Found new task: " + (((ITask)o).Name), EventLogEntryType.SuccessAudit);  
                                    tasks.Add((ITask)o);
                                }
                            }

                            catch (Exception e)
                            {
                                Logger.Instance.Log(e);
                            }
                        }
                    }
                }

                catch (Exception e)
                {
                    Logger.Instance.Log(e);
                }
            }

            return tasks;
                
        }
    }
}
